"Flight for Life" by Marie Bartlett Maher is a hyped up true account of Heli-EMS in the states. "Sea Wolves" by Daniel E. Kelly about Huey pilots who flew Seals in Nam. If you want good fiction, James Clavell's "Whirlwind" is losely based on Bristow trying to get their helicopters out of Iran when the Shaw left in 1979, awesome read! Dale Brown, ex-Air Force writes pilot books, "Hammerheads" is based on tilt-rotors. Tom Clancy always has a little heli action too.
Non-fiction Canadian Heli-bush-flying can be found in Peter Corley Smith's "Ten Thousand Hours" and "Helicopters:The British Columbia Story".
Good luck.